4 November 2013

Rosemary Stanton: Fat facts

LAST month Dr Aseem Malhotra, a cardiology registrar, wrote an opinion article in the BMJ claiming that advice to reduce cholesterol “has, paradoxically, increased our cardiovascular risks” and “saturated fat is not the major issue for cardiovascular disease”.

In the same week, ABC’s Catalyst program weighed into the argument, with claims that the world has been misled by the demonisation of saturated fat.

Catalyst, which aired the second part of the program last week, relied on the opinion of a journalist and four US experts — a nutritionist, two cardiologists and a physician — but failed to note that three of the experts market a range of “alternative” products via their websites (www.jonnybowden.com, www.drsinatra.com, www.proteinpower.com), including diet “aids” (with “slimming” claims), anti-ageing, “brain power” and detox supplements, plus a variety of bars, shakes, drinks and powders. One product even claims its citrus bergamot content will lower triglycerides, blood sugar and inflammatory LDL (low-density lipoprotein) cholesterol and raise HDL (high-density lipoprotein) cholesterol.

On the topic of saturated fat, both the BMJ article and Catalyst attack the published reports of Ancel Keys’ Seven Countries studies (12 000 men; 16 populations) on dietary patterns and coronary heart disease begun in the 1960s.

These and other studies reported a strong correlation between intake of saturated fat and serum cholesterol, which led to official guidelines recommending lean meats and low fat dairy products and fewer fried foods, cakes, biscuits and fatty snacks. Food companies responded by developing and marketing a range of fat-reduced products, such as cookies (often giant-sized), desserts, yoghurts, sweet and savoury snacks and confectionery. Most replaced some of the fat with sugar or highly refined starches.

In the US, intake of fat did not fall, but because the extra sugar and starch pushed energy intake up by 7% in men and 22% in women, the percentage of energy from fat fell slightly as the population grew fatter.

The Australian Dietary Guidelines have always specifically recommended limits to sugar and salt. Swapping one source of kilojoules (saturated fatty acids) for another (sugars and starches) is not likely to produce any great health breakthrough!

Malhotra quotes a couple of studies claiming total cholesterol is not a risk factor in a healthy population. Many other studies have found the opposite. A recent systematic Cochrane review concluded that reducing dietary saturated fat lowered the risk of cardiovascular events by 14% among more than 65 000 participants of whom 4585 had a cardiovascular event over a 2-year period. Benefits occurred in men but not in women. Such results are not dramatic, but they do not support Malhotra’s claim that “advice to remove saturated fat has increased our cardiovascular risks”.

In fact, it would not be possible to “remove” saturated fat since some is found in any food that contains fat. The real problem is that trying to reduce or calculate saturated fat intake suffers from a lack of specificity.

Foods contain a mixture of saturated, monounsaturated and polyunsaturated fatty acids. They also differ in many other nutritionally important ways. For example, a tablespoon of lard, 35 g of cheddar cheese, 35 g of white chocolate, a small 145 g piece of rump steak or 70 g of potato crisps all contain the same amount of saturated fat.

With polyunsaturated fats, there is a need (often ignored) to distinguish between foods containing omega 3 and omega 6 polyunsaturates. Delve into the omega 3s and you find different actions of those from plants such as walnuts, canola and chia seeds and the longer chain omega 3s in seafood. The omega 6s also keep different company when liquid oils are made into spreads. Remember too that early studies about polyunsaturated fats related to spreads containing large quantities of the trans fat, elaidic acid.

Simply tallying the amount of any type of fat consumed is a totally inadequate way to judge any diet. Such issues influenced the NHMRC to seek evidence and give advice about foods rather than individual nutrients (www.eatforhealth.gov.au). It has also led to studies and evidence backing Mediterranean-style or healthy Japanese eating patterns — both shown to be healthy over many years and recommended by Ancel Keys.

And that’s the message to pass on to patients.

Dr Rosemary Stanton OAM is a leading Australian nutritionist.

24 thoughts on “Rosemary Stanton: Fat facts”

Rosemary, sensible as always. Maryanne Demasi’s breathless “debunking” of established science about fats, cholesterol and heart disease on Catalyst was long on hostile rhetoric and anecdotes, but short on science and facts. The important relationship with other risk factors was hardly considered, and the conflicts of interest of the interviewees never mentioned.

To paraphrase the immortal Sir Humphrey , it would take a very courageous doctor to advise his/her patients to follow Catalyst’s advice. But I am sure that will be many of Dr Google’s patient who will follow it , just to spite the big pharmas’ ” conspiracy “

Rosemary, I am totally confused; after Catalyst, I stopped my statin. (This may have upset my Metoprolol (pulmonary hypertension.)) So what do I eat now? I suppose, In the circumstances, anything I like!!

Thank you for a rational voice in this discussion. It DOES seem that statins, like antibiotics, are over-used. That does not make either therapy a ”scam” or Big Pharma plot. Pharmaceutical companies are always trying to expand their markets – as are all manufacturers (including ”natural therapies”, vitamins, homeopathic manufacturers). It is up to prescribers to follow best evidence. It seems that statins are effective at improving outcomes for familial hypercholesterolaemia and secondary prevention (established coronary disease), but not for primary prevention. Stopping smoking and getting active are both great for primary prevention. NOne of this means that we should all go out and eat more saturated fat, though. It must be frustrating for Rosemary Stanton, having spent a whole career practising both the clinical and academic science of nutition and diet, to see all the amateurs pushing their theories.

“On the topic of saturated fat, both the BMJ article and Catalyst attack the published reports of Ancel Keys’ Seven Countries studies (12 000 men; 16 populations) on dietary patterns and coronary heart disease begun in the 1960s.”

Looking closely at this study gives good reason for this criticism. This study was integral to the formulation of the Diet/ Heart hypothesis. There were 12,000 men enrolled in the study but dietary data was obtained for only a small sample. In 1989 Keys reported “In the United States, employees of the U.S. Railroad in the State of Minnesota cooperated in the dietary survey of the study. This survey was carried out during 1960-62…A total of 30 men weighed and recorded their food consumption for 1 day.” This was suppose to characterise the diets of the 2,571 U.S men enrolled in the study.

Also, the Japanese cohorts consisted of a total of 1,010 men, however the dietary data characterizing the Japanese was gathered from 4 day food records of 24 men in a village in the interior of Japan and 8 men in a coastal village.

After 10 years, Keys reported the coronary death rate was correlated strongly with saturated fat intake, with the percentage of calories supplied by sucrose in the average diets of the cohorts and to the percentage of dietary calories from animal proteins. As saturated fat, sucrose and animal protein intakes were all strongly associated with CHD, no single variable can be said to be more important than another.

When one examines the evidence in relation to questions such as diet and heart disease one is supposed to look at the totality of the evidence, not just one or two studies. There is moreover a heirarchy of evidence which the NHMRC classifies from Level 1 – meta-analyses of randomised controlled trials (the highest level) down to Level IV – case series (lowest level). In relation to intervention studies, large scale, long term interventions at the level of entire countries carry real weight, particularly if the intervention is well defined and the effect is large.

In the period from 1972 to 2007 in Finland, for example, there was an 80% reduction in cardiovascular mortality in males under 65 years of age. This correlated with a 20% reduction in total cholesterol levels and a major decrease in saturated fat intake. See: Thirty-five-year trends in cardiovascular risk factors in Finland. International Journal of Epidemiolology, 2010 Apr.(39)2: 504-18. (Free full text article).

The analysis of saturated fat and cardiovascular disease on Catalyst was hardly a balanced view of all the evidence. It was a bit like concluding that cholera is not a water-borne disease because there were some methodological flaws in the original 1853 study which linked a cholera outbreak to a particular London water pump.

Ancel Keys study was only conducted on men aged 40 years of age. He also ‘cherry’ picked countries that fitted the model he wanted to present. When they plotted other countries data, there was no correlation between saturated fat. cholesterol and people dying from heart disease. How do you explain this?

From what I have found out, it makes a lot of sense to eat like our forebears did for thousands of years. Eating “modern” food, while convenient, is rarely good for your health. That more than anything is one of the most compelling arguments for avoiding sugar, eating natural fats and especially avoiding things like margarine.

How then Rosemary would you explain the Tokaleau Island Migrant Study where they ate about 50-60% of their calories from saturated fat (Coocnuts) and had no heart disease, diabetics or obesity. Right up until they adopted the Western diet…

On a personal note I have never felt better since I dumped sugar (added fructose to be specific) and started eating real fats again – butter, coconut oil etc. I’ve lost 14 kg, have so much energy, 3pm low blood sugar ‘melt downs’ are a thing of the past and I’m just calmer and happier all round. 7 months on I’m even naturally losing my desire to eat carbs.

You can write any number of articles you want Rosemary, but your thinking is so outdated that I wonder what’s behind it? People are getting sick and dying horrible deaths because of what dietitians, health authorities and medical professionals have recommended for the past 30-40 years ie: low fat, high sugar, seed oils – frankenfood.

While i was eating suagr I was ravenously hungry all the time, despite obviously having enough excess energy (body fat!) to feed my body for a long time! As soon as I ditched the sugar and added back the real fats (particularly coconut oil) my overall calories dropped significantly. At least I assume they did because I refuse to ever count calories. all i know is that i put about half the food i used to into my mouth because I’m NOT HUNGRY.

The current dietary advice simply ISN’T WORKING. Please open your heart and mind and at least look into why so many people are ignoring it and moving back to real food with amazing results.

In the Tokelau migrant study the observed levels of tolal cholesterol were around 30% lower than would have been predicted in a European population based upon their dietary percentage intake of saturated fat. The likely reason for this is thousands of years of natural selection. Brown and Goldstein won the 1985 Nobel Prize for Medicine and Physiology for showing that individuals and groups differed in their ability to metabolise cholesterol based upon the number of cholesterol receptors in their livers.

It is thus quite misleading to base arguments around saturated fat intake upon populations which metabolise it differently to the target population. The Eskimos and Tokelauans would likely have seen those individuals who could not effectively metabolise saturated fat without unduly raising their cholesterol succumb to cardiovascular disease and leave the gene pool. Over thousands of years even a one percent selection pressure on a gene can completely change its frequency in a population from rare to almost universal.

One might as well argue that UV radiation is not harmful because the Tokelauans never seemed to get sunburn or skin cancer.

See Cholesterol Coconuts and Diet on Polynesian Atolls: a natural experiment: The Pukapuka and Tokelau island studies. The American Journal of Clinical Nutrition, 34 (August 1981) pp1552-61.

Ah – the fructose-is-poison zealots are out. ONe would need the patience of a saint to continue a rational discussion in the midst of all the self-appointed dietary experts that have emerged in this debate. Diet is an area ripe for simplistic messages, because the rational advice of ”balance” isn’t attractive enough. So, the data shows that statins are effective for some situations and not others. How did this translate into eating more saturated fat? Kudos to Prof Stanton for maintaining a rational, and evidence-based, approach.

Rosemary Stanton along with the Heart Foundation are on shaky ground with the current and growing findings pointing away from Saturated Fats being the problem with CVD and back onto the Polyunsaturated Fats and particularly the Omega 6’s.

This very current review article (May 2013) is a great summation of this topic.

Dietary Fats and Health: Dietary Recommendations in the Context of Scientific Evidence

Prof G Lawrence Dept Biochemistry, Long Island University, NY

..the evidence of dietary saturated fats increasing CAD or causing premature death was weak. Over the years, data revealed that dietary saturated fatty acids (SFAs) are not associated with CAD and other adverse health effects or at worst are weakly associated in some analyses when other contributing factors may be overlooked. Several recent analyses indicate that SFAs, particularly in dairy products and coconut oil, can improve health. The evidence of v6 polyunsaturated fatty acids (PUFAs) promoting inflammation and augmenting many diseases continues to grow, whereas v3 PUFAs seem to counter these adverse effects. The replacement of saturated fats in the diet with carbohydrates, especially sugars, has resulted in increased obesity and its associated health complications… The adverse health effects that have been associated with saturated fats in the past are most likely due to factors other than SFAs, which are discussed here. This review calls for a rational reevaluation of existing dietary recommendations that focus on minimizing dietary SFAs, for which mechanisms for adverse health effects are lacking. Advances in Nutrition. 4: 294–302, May 2013.

Increasing public awareness of important health issues, transparency and rigorous independent scrutiny of established scientific “facts” are vitally important. Like many others, I abhor the tendency to over-medicalise, and the increasing pressure from many sources to over-diagnose and to over-treat. Having said all that, I was disappointed in Catalyst’s treatment of the issues raised – in both part 1 and 2. I thought it was sensationalised and unbalanced, and therefore irresponsible to air. Using emotive terms such as “toxic”, “organised crime” and “conspiracy” is not helpful to anyone.

On the positive side, it has brought the topic of heart health to the public’s attention, and provided a good opportunity for doctors to reassess their patients’ absolute cardiovascular risks, review their need for medication, and to provide education and advice on all lifestyle risk factors. The shows also emphasised the importance of regular exercise and a diet low in refined sugars. All good things.

Natural foods produced naturally consumed in limited quantities by people engaged in moderate physical activity for thousands of years did not cause heart disease nor obesity, so it is not logical that saturated fat, dairy foods, meat, cereals, fruit and vegetables , oils, oilseeds, foods produced naturally have suddenly become poisonous in the last few decades

The only correlation which is not drawn from studies funded by drug companies, including sellers of artificial remedies, margarine companies , and other self-interested groups is that the increase in consumption of unnatural refined, take-away and fast foods, artificial chemicals, combined with a sedentary lifestyle , have resulted in the diseases of the last few decades.

Take-away foods in particular may have little quality control over the amount of rancid fat, sugar, artificial chemicals, harmful bacteria .

If you want to be healthy, then prepare natural foods, eat in moderate quantity, exercise, and avoid artificial cigarettes, artificial drinks , and artificial chemicals.

There is no cure, whether drug , chemical, surgical if you continue to ingest greater quantities of fat , sugar , or protein that you require-this is the message that no-one wants to hear.

I sometimes wonder if people who comment actually read the piece to which they are adding their comments.

I stated quite plainly that Australia’s Dietay Guidelines have always recommended ‘avoiding too much’ or ‘limiting’ added sugar. The guidelines have never promoted sugar and never suggested replacing saturated fats with sugar.

Also many of the comments relating to the work of Ancel Keys are merely repetitions of website blogs and material published in various books promoting a high fat diet. Having met and discussed many things with Ancel Keys when he was alive, I can reassure Jennifer Elliot that he did not only examine the diets of 30 men for one day. Indeed, Keys was able to do something we can only dream of these days. His studies in Crete had dietitians go and live with families, noting everything they consumed, weighing portions and leftovers and recording this meticulously. They did not do this with all 16,000 men in the 7 Countries Study but they did it with some to check on the accuracy of the dietary records on which they were relying. These days we have to make do with questionnaires of 24 hour intake or food frequency intakes of a small percentage of the foods available.

In discussing obesity, it’s also important not to ignore the huge changes in physical activity that have occurred over the last 40 -50 years.

It’s also important to note (as Ancel Keys did) that there is no single perfect diet. As he pointed out all those years ago, the diet of Crete in the 1950s (high in total fat, but low in saturated fat) or the diet of Japan at that time (low in fat and, hence also low in saturated fat) are both conducive to low rates of coronary heart disease.

The two examples I gave were from Key’s own data. Also, the total dietary data was collected from less than 4% of the 12,763 men enrolled in the study and Keys admitted that detailed data on food consumption patterns were published for only 9 of the 16 cohorts. There may have been excellent collection procedures in some cohorts but obviously not in Japan and the US. And we don’t know about the 9 cohorts for which data has not been published.

You say the study showed a strong correlation between sat fat intake and CHD. Keys also reported strong correlations with sucrose and animal protein intake and CHD.

But what can we take from these results and similar studies? Indirect methods of study cannot show that a variable such as saturated fat increases risk of disease, only that it is associated, in a statistical sense, with increased incidence. The former implies cause and effect and statistical associations do not constitute proof of a cause and effect relationship. A ‘strong’ or ‘significant’ correlation in this context refers to an estimate, based on statistical probabilities, of the likelihood of the association being due to chance.

As you say, official dietary guidelines recommended changes based on this and other studies. I believe that there is a need to question and reassess the science behind these dietary recommendations, as the Catalyst program has done.

Ancel Keys study is only one of many which show similar trends. For example in the China wide 64 cohort Oxford-Cornell-China Study in the 1980s saturated fat intake was one third that of the US level and cholesterol levels in China were 40% below the US. The age adjusted ‘heart disease prevalence in China was one sixteenth the US rate. See Diet, lifestyle, and the etiology of coronary artery disease: the Cornell China study. Am J Cardiol. 1998 Nov 26;82(10B):18T-21T.

The study was designed by Richard Peto who had also worked as the statistical epidemiologist on Richard Doll’s landmark study linking smoking and lung cancer. Peto was given a professorial chair at Oxford and knighted for his efforts.

Similarly, in the first 6400 patient Framingham Study nobody who maintained a total cholesterol of 3.9mmol/L or lower ever suffered a coronary event over the 30 years of the study.

This work has been translated into intervention studies such as Dean Ornish’s study reversing coronary plaque and Caldwell Esselstyn’s study which prevented any further coronary events over 12 years in a group of 20 patients who were deemed to have inoperable heart disease at America’s leading heart surgery centre.

Subsequently of 44,000 adults sampled across China in 2008 ome 25% were either diabetic or prediabetic.

Like a/a I stopped my statin after the Catalyst programme only to start it again when I heard and read the criticisms tyhat followed.. Also like her/him I was told I had pulmonary hypertension, a nasty, but now they say it is diastolic dysfunction! Has this anything to do with fat, I do not know. KBO

Rosemary,The fact that Crete and Japan had low rates of CVD and low consumption of saturated fat is a misinterpretation of data. Both places would have had high consumption rates of long chain omega 3s and no elaidic acid. However when you consider the high consumption rates of saturated fat in France and their low rates of CVD and general life expectancy the idea of saturated fat being bad for humans looks less than convincing. Also consider the Amish Like the French they consume high amounts of saturated fat and protein but no elaidic acid. Their life expectancy is no lower that the rest of the USA despite the fast there is a fair amount of inbreeding within the Amish. Their rates of CVD are no particularly high.http://www.abc.net.au/radionational/programs/healthreport/health-of-the-…